Sandinista General May Be Chamorro's Army Chief : Nicaragua: The reported choice of Humberto Ortega could provoke a split in her coalition. The move is described as temporary.

MANAGUA, Nicaragua — President-elect Violeta Barrios de Chamorro is expected to announce in her inaugural address today that she will name the Sandinista defense minister, Gen. Humberto Ortega, to a top position in the country's military.

The Baltimore Sun, quoting a Sandinista Foreign Ministry official and a senior editor of Chamorro's La Prensa newspaper, said Chamorro will assume the post of defense minister upon becoming president and will name Ortega as chief of staff, the second-highest military position. Gen. Ortega is the brother of Sandinista President Daniel Ortega, defeated by Chamorro in the Feb. 25 elections.

La Prensa Editor Horacio Ruiz said that the appointment will be temporary, perhaps for six months, and is aimed at guaranteeing a peaceful transition.

Both the Foreign Ministry official and Ruiz said Chamorro decided to keep Gen. Ortega to forestall a series of strikes by pro-Sandinista unions and possible insubordination in the Sandinista-dominated army.

But keeping him as army commander likely will heighten divisions inside Chamorro's ruling coalition and could threaten an agreement with the U.S.-backed Contras, who have promised to disarm by June 10, ending nine years of civil war.

The Contras and members of her coalition have demanded that Sandinista loyalists be purged from the army.

"There are some extremists who want the Sandinistas wiped out in one fell swoop," a source close to Chamorro told the Associated Press, describing some factions in the National Opposition Union (UNO). "That can't be. He (Ortega) will be eased out but not for a while."

UNO's political council, headed by Vice President-elect Virgilio Godoy, alluded to the appointment in a communique Tuesday that said the council "would not support such a decision, nor would it be responsible for its consequences."

The ruling National Sandinista Liberation Front announced Monday that the military and police could no longer hold posts in the party, thus theoretically removing party control from the Defense and Interior ministries.

But the Godoy faction has been complaining that men such as Humberto Ortega can remain party members, even though they no longer occupy party posts, and that the party will remain in control.

About 30 senior military and police officials have been forced to resign, including Ortega, who was one of the nine members of the party's ruling directorate, the Foreign Ministry source said.

"I think it was essential that Mrs. Chamorro show the Sandinistas and the army that she is serious about reconciliation. Besides, Ortega is a man who can keep the army in line," said the official, a senior member of the Sandinista party.

Virtually all army officers above the rank of captain and key officers in the Interior Ministry are members of the Sandinista party.

UNO faces a test of unity in the National Assembly while Cabinet appointees, due to be sworn in shortly after Chamorro's inauguration, have yet to be officially announced.

The first test came Tuesday afternoon, when the new National Assembly met to elect a president. UNO's official choice is Myriam Arguello, a 64-year-old lawyer from the People's Conservative Alliance, one of 14 parties in the UNO coalition. Arguello earlier received 28 votes at a caucus of UNO's 51 deputies, to 23 for Chamorro adviser Alfredo Cesar, a former member of the Contras' directorate and a man with his sights set on running for president in the 1996 elections.

Arguello is backed by Godoy, and the Sandinistas have hinted that their 39 deputies might vote for Cesar to encourage a split in UNO ranks, even though Cesar is not a Sandinista favorite because of his Contra connections.